1. Technical Field
This application claims a priority to Japanese Patent Application No. 2014-173631 filed on Aug. 28, 2014 which is hereby expressly incorporated by reference in its entirety.
Several aspects of the present invention relate to a solar cell module, a timepiece, and an electronic device.
2. Related Art
Since periodic replacement of batteries is no longer required, a solar timepiece including a solar cell has been widely used. JP-A-2001-284618 discloses the solar timepiece including the solar cell. According to the disclosure, in order to secure a sufficient voltage, the solar timepiece includes a support substrate and the solar cell having multiple solar cell elements formed on a surface of the support substrate. The multiple solar cell elements are serially connected to each other, thereby increasing a solar cell power generation voltage used for the solar timepiece. The support substrate is a glass plate. A lower electrode layer, a power generation layer, and an upper electrode layer are formed on the glass plate.
The support substrate disclosed in JP-A-2001-284618 is the glass plate. The glass plate is a material which is less likely to be processed thinly. A thin and light electronic device such as a wrist watch is easy to use. If the support substrate is thinner, it is possible to achieve the thinner and lighter electronic device such as the wrist watch. Therefore, when the thinner solar cell is needed, a structure is conceivable which forms the support substrate using a metal plate and uses the support substrate as a lower electrode.
With regard to this structure, a method of serially joining the multiple solar cell elements as described above includes a method of cutting a single solar cell panel so as to be divided into the multiple solar cell elements. The solar cell panel employs a type in which a conductive support layer and a transparent conductive film stacked thereon via a power generation film are respectively used as electrodes. In this case, the solar cell panel is cut on the support substrate, and is divided into multiple pieces (solar cell panels). However, when the solar cell panel is divided into multiple pieces in this way, the respective pieces have to be assembled to the electronic device such as the wrist watch, thereby causing poor productivity.
Therefore, a method is conceivable in which the respective pieces are bonded to a thin substrate and the substrate having the respective pieces bonded thereto is assembled to the electronic device such as the wrist watch. However, when the substrate is thin, the rigidity of the substrate decreases, and the substrate having the respective pieces bonded thereto is bent, thereby causing a problem of difficult assembly. For this reason, there has been a demand for a solar cell module in which the substrate having the respective pieces bonded thereto is likely to be assembled even when the substrate itself is likely to be bent.